Windscreen wiper device

ABSTRACT

A windscreen wiper device ( 1 ) comprising an elastic, elongated carrier element, as well as an elongated wiper blade ( 2 ) of a flexible material, which can be placed in abutment with a widescreen to be wiped, which wiper blade ( 2 ) includes opposing longitudinal grooves ( 3 ) on its longitudinal sides, in which grooves ( 3 ) spaced-apart longitudinal strips ( 4 ) of the carrier element are disposed, wherein neighbouring ends of said longitudinal strips ( 4 ) are interconnected by a respective connecting piece ( 6 ), which windscreen wiper device comprises a connecting device ( 7 ) for an oscillating arm ( 8 ), wherein said oscillating arm ( 8 ) is pivotally connected to said connecting device ( 7 ) about a pivot axis near one end, with the interposition of a joint part ( 12 ), with the special feature that said connecting device ( 7 ) is positioned at least substantially within said joint part ( 12 ).

The present invention relates to a windscreen wiper device comprising anelastic, elongated carrier element, as well as an elongated wiper bladeof a flexible material, which can be placed in abutment with awindscreen to be wiped, which wiper blade includes opposing longitudinalgrooves on its longitudinal sides, in which grooves spaced-apartlongitudinal strips of the carrier element are disposed, whereinneighbouring ends of said longitudinal strips are interconnected by arespective connecting piece, which windscreen wiper device comprises aconnecting device for an oscillating arm, wherein said oscillating armis pivotally connected to said connecting device about a pivot axis nearone end, with the interposition of a joint part.

Such a windscreen wiper device is known from German patent publicationno. 101 30 903 (Robert Bosch GmbH). This prior art windscreen wiperdevice is designed as a “yokeless” wiper device, wherein no use is madeof several yokes pivotally connected to each other, but wherein thewiper blade is biassed by the carrier element, as a result of which itexhibits a specific curvature. This known device has a first couplinghalf fixed to the oscillating arm, as well as a second coupling halffixed to the wiper blade, wherein two parallel interspaced supportingwalls of the second coupling half are oriented in the longitudinaldirection of the wiper blade. Each end of a pivot pin for a joint part,which is mounted on the pivot pin in a manner that permits it to swingbetween the supporting walls and which is provided for connecting theoscillating arm, is held in these supporting walls. In order to obtainprotection against environmental influences such as snow, ice and dust,the oscillating arm is u-shaped in the area of its coupling half,whereby the U-base covers the supporting (protective) walls and bothU-limbs cover the outer sides of these supporting walls.

A disadvantage of the windscreen wiper device known from theabove-mentioned German patent document is that, due to high forcesexerted in practice on the connection between the connecting device andthe oscillating arm, the reliability of said connection appaers todiminish with the passage of time, resulting in play between theconnecting device and the oscillating arm. Such a play in practice hasproven to lead to frictional contact between these parts and thereforeto wear. A further disadvantage thereof is that many constructionalparts are involved in the connection between the connecting device andthe oscillating arm, making the known windscreen wiper device laboriousto manufacture and therefore relatively costly.

The object of the invention is to overcome these drawbacks of the priorart as indicated above, in particular to provide a windscreen wiperdevice wherein the connecting device and the oscillating arm areinterconnected in a simple though durable and solid manner.

In order to accomplish that objective, a windscreen wiper device of thetype referred to in the introduction is characterized in that saidconnecting device is positioned at least substantially within said jointpart. Particularly, this enables to attach said joint part to saidconnecting device by protrusions of said connecting device at thelocation of said pivot axis, said protrusions pivotally engaging inrecesses provided in said joint part. These protrusions that function asbearing surfaces are spaced far apart, so that the forces exerted on thebearing surfaces will be relatively low. As these protrusions replacethe pivot pin as used in the known windscreen wiper device discussedabove, less constructional components are used in connecting theconnection device and the oscillating arm together. For an optimalarticulation at the location of the protrusions the distance betweenthese protrusions divided by the length of the wiper blade, from tip totip, is larger than 0.02.

In one preferred embodiment of a windscreen wiper device according tothe invention said joint part has an at least substantially U-shapedcross-section at the location of its attachment to said connectingdevice, wherein said joint part in each leg of said U-shapedcross-section is provided with a recess provided coaxially with saidpivot axis. Preferably, the protrusions extend outwards on either sideof said connecting device (that is, outwardly in lateral direction withrespect to the oscillating arm), wherein the protrusions are at leastsubstantially cylindrical. Particularly, the recesses arecorrespondingly shaped.

In another preferred embodiment of a windscreen wiper device accordingto the invention said joint part is made of plastic, which includes anysynthetic material having some flexibility.

In another preferred embodiment of a windscreen wiper device accordingto the invention said joint part comprises at least one resilient tongueengaging in a correspondingly shaped hole provided in said oscillatingarm. Preferably, the oscillating arm has an at least substantiallyU-shaped cross-section at the location of its connection to said jointpart, wherein said hole is provided in a base of said U-shapedcross-section.

In another preferred embodiment of a windscreen wiper device accordingto the invention said joint part comprises at least two lateralresilient tongues extending outwardly, wherein the oscillating arm hasan at least substantially U-shaped cross-section at the location of itsconnection to said joint part, and wherein each tongue engages in acorrespondingly shaped hole provided in a leg of said U-shapedcross-section.

While mounting the oscillating arm onto the connecting device/jointpart, the resilient tongue(s) is/are initially pushed in against aspring force and then allowed to spring back into said hole(s), thussnapping, that is clipping the resilient tongue(s) into the hole(s).

In another preferred embodiment of a windscreen wiper device accordingto the invention said hole(s) has/have a closed circumference. Such (a)closed hole(s) enhance(s) the retention of the oscillating arm onto theconnecting device/joint part in all directions, particularly bothhorizontally and vertically.

In another preferred embodiment of a windscreen wiper device accordingto the invention the oscillating arm has an at least substantiallyU-shaped cross-section at the location of its connection to said jointpart, and wherein each leg comprises clamping members which engage rondlongitudinal sides of said joint part that face away from each other.These clamping members being preferably formed as inwardly bended edgesintegral with the legs of the U-shaped cross-section, serve to furtherenhance the retention of the oscillating arm onto the connectingdevice/joint part in vertical direction, that is perpendicular to thelongitudinal direction of the oscillating arm.

The invention will now be explained in more detail with reference tofigures illustrated in a drawing, wherein:

FIG. 1 is a perspective, schematic view of a preferred embodiment of awindscreen device in accordance with the invention;

FIGS. 2 and 3 show details of the windscreen wiper device of FIG. 1,wherein various successive steps are shown for fitting an oscillatingwiper arm to a connecting device using two different types of jointparts (“spacers”);

FIG. 4 is a perspective and schematic view of an end of an oscillatingwiper arm used in FIG. 3.

FIG. 1 shows a preferred variant of a windscreen wiper device 1according to the invention. Said windscreen wiper device is built up ofan elastomeric wiper blade 2, in the longitudinal sides of whichopposing longitudinal grooves 3 are formed, and of longitudinal strips 4made of spring band steel, which are fitted in said longitudinal grooves3. Said strips 4 form a flexible carrier element for the rubber wiperblade 2, as it were, which is thus biassed in a curved position (thecurvature in operative position being that of a windscreen to be wiped).Neighbouring ends 5 of strips 4 are interconnected on either side of thewindscreen wiper device 1 by means of connecting pieces 6 functioning asclamping members. In this embodiment, the connecting pieces 6 areseparate constructional elements, which may be form-locked (“positivelocking” or “having positive fit”) as well as force-locked to the ends 5of strips 4. In another preferred variant, said connecting pieces 6 arein one piece with the strips 4 made of spring band steel. In the lattercase said connecting pieces form transverse bridges for the strips 4, asit were.

The windscreen wiper device 1 is furthermore built up of a connectingdevice 7 of plastic material for an oscillating wiper arm 8. Connectingdevice 7 comprises clamping members 9 that are integral therewith, whichengage round longitudinal sides 10 of the strips 4 that face away fromeach other, as a result of which the connecting device 7 is firmlyattached to the unit consisting of wiper blade 2 and strips 4. Theoscillating wiper arm 8 is pivotally connected to the connecting device7 about a pivot axis near one end, and that in the following manner.

With reference to FIG. 2 the connecting device 7 comprises twocylindrical protrusions 10 extending outwards on either side of saidconnecting device 7 (FIG. 2 a). These protrusions 10 pivotally engage inidentically shaped cylindrical recesses 11 of a plastic joint part 12(FIG. 2 b). Said protrusions 10 act as bearing surfaces at the locationof a pivot axis in order to pivot the joint part 12 (and the oscillatingwiper arm 8 attached thereto) about said pivot axis near one end of saidarm 8. The protrusions 10 are preferably in one piece with theconnecting device 7; in the alternative, the protrusions 10 are part ofa single pivot pin perpendicular to the connecting device 7. Saidconnecting device 7 may be equipped with a cover or cap in order toobtain an aesthetic appearance thereof, to avoid sharp edges and toprovide protection against UV-light etcetera. The joint part 12comprises two lateral resilient tongues 13 extending outwardly, whilethe oscillating arm 8 has a U-shaped cross-section at the location ofits connection to said joint part 12, so that each tongue 13 engages inan identically shaped hole 14 provided in a leg 15 of said U-shapedcross-section (FIG. 2 c).

FIGS. 3 a, 3 b and 3 c correspond to FIGS. 2 a, 2 b and 2 c,respectively, with the difference that one resilient tongue 13 in FIG. 3fitting in a hole 14 provided in a base 16 of the U-shaped cross-section(FIG. 3 c).

Referring to both FIGS. 2 and 3, while mounting the oscillating wiperarm 8 onto the connecting device 7/joint part 12, the resilienttongue(s) 13 is/are initially pushed in against a spring force and thenallowed to spring back into said hole(s) 14, thus snapping, that isclipping the resilient tongue(s) 13 into the hole(s) 14. This is aso-called bayonet-connection.

Each leg 15 of the U-shaped ross-section comprises clamping memberswhich engage rond longitudinal sides of said joint part 12 that faceaway from each other. In FIGS. 2, 3 and 4 these clamping members areformed as inwardly bended edges 17 integral with the legs 15 of theU-shaped cross-section, serving to further enhance the retention of theoscillating arm 8 onto the connecting device 7/joint part 12 in verticaldirection, that is perpendicular to the longitudinal direction of theoscillating wiper arm 8.

Possibly, a spoiler 18 is furthermore provided (FIG. 1).

In order to achieve a good connection at the location of the protrusions10, the distance between these protrusions 10 (from tip to tip) dividedby the length of the wiper blade 2 (from tip to tip) is larger than 0.02(2%). Said distance between the protrusions 10 preferably varies between10 and 20 mm.

The invention is not restricted to the variants shown in the drawing,but it also extends to other embodiments that fall within the scope ofthe appended claims.

1. A windscreen wiper device comprising an elastic, elongated carrierelement, as well as an elongated wiper blade of a flexible material,which can be placed in abutment with a windscreen to be wiped, whichwiper blade includes opposing longitudinal grooves on its longitudinalsides, in which grooves spaced-apart longitudinal strips of the carrierelement are disposed, wherein neighbouring ends of said longitudinalstrips are interconnected by a respective connecting piece, whichwindscreen wiper device comprises a connecting device for an oscillatingarm, wherein said oscillating arm is pivotally connected to saidconnecting device about a pivot axis near one end, with theinterposition of a joint part, characterized in that said connectingdevice is positioned at least substantially within said joint part.
 2. Awindscreen wiper device according to claim 1, wherein said joint part isattached to said connecting device by pivotally engaging protrusions ofsaid connecting device at the location of said pivot axis in recessesprovided in said joint part.
 3. A windscreen wiper device according toclaim 2, wherein said joint part has an at least substantially U-shapedcross-section at the location of its attachment to said connectingdevice, and wherein said joint part in each leg of said U-shapedcross-section is provided with a recess provided coaxially with saidpivot axis.
 4. A windscreen wiper device according to claim 2, whereinthe protrusions extend outwards on either side of said connecting deviceand wherein the protrusions are at least substantially cylindrical.
 5. Awindscreen wiper device according to claim 1, wherein said joint part ismade of plastic.
 6. A windscreen wiper device according to claim 1,wherein said joint part comprises at least one resilient tongue engagingin at least one correspondingly shaped hole provided in said oscillatingarm.
 7. A windscreen wiper device according to claim 6, wherein theoscillating arm has an at least substantially U-shaped cross-section atthe location of its connection to said joint part, and wherein said holeis provided in a base of said U-shaped cross-section.
 8. A windscreenwiper device according to claim 6, wherein said joint part comprises atleast two lateral resilient tongues extending outwardly, wherein theoscillating arm has an at least substantially U-shaped cross-section atthe location of its connection to said joint part, and wherein eachtongue engages in a correspondingly shaped hole provided in a leg ofsaid U-shaped cross-section.
 9. A windscreen wiper device according toclaim 6, wherein said at least one hole has a closed circumference. 10.A windscreen wiper device according to claim 1, wherein the oscillatingarm has an at least substantially U-shaped cross-section at the locationof its connection to said joint part, and wherein each leg comprisesclamping members which engage around longitudinal sides of said jointpart that face away from each other.
 11. A windscreen wiper deviceaccording to claim 1, wherein said connecting device is made of plastic.